South of the Border, West of the Sun by Haruki Murakami

This book tells the story of Hajime, whose happy family life is disrupted when a woman he loved in childhood comes back into his life. The story is fascinating, and in some senses, only covered in its contours: there's a lot of Shimamoto's history and circumstances that's simply left unexplained. The book is far more interested in the emotional impact of her interactions with Hajime than in telling her story.